Firing mechanism for automatic firearms



Oct. 1. 1940.

v. HOLEK 2,216,412

FIRING MECHANISM FOR AUTOMATIC FIREARMS Filed July 14, 193" FI J Fig.3

Fig.5 F196 3/ Z7 VZMzM Z Patented Oct. 1, 1940 UNITED STATES FIRINGMECHANISM FOR AUTOMATIC FIREARMS Vaclav Holek, Zabovresky, Brunn,Czechoslovakia, assignor to Ceskoslovenska Zbrojovka, a. s.,

Brno, Brunn, vakian company Czechoslovakia, a Czechoslo- ApplicationJuly 14, 1937, Serial No. 153,653 In Czechoslovakia July 20, 1936' 7Claims.

This invention relates to firing mechanism for automatic firearms.

In known firing mechanisms the setting means for permitting the firingof single shots or a series of shots and the means for locking thefiring mechanism are operated by means of separate levers, usuallydisposed laterally of the trigger. The defect of such a firing mechanismis not only its complicated construction, but also the difficulty ofmanipulation, which requires some considerable time for operating themembers which are separated from one another, such as the trigger andthe locking mechanism and the aforesaid setting means.

These defects are eliminated by theconstruction according to theinvention, in which there is provided firing mechanism for automaticfirearms for firing single shots or a series of shots, wherein thetrigger comprises a rod or member mounted in a casing in such a manneras to be displaceable longitudinally and rotatable, the longitudinaldisplacement of the said rod being utilized to operate a sear to permitfiring and the rotary movement being utilized to set the firingmechanism into a position for firing single shots or a series of shotsor into a position to lock the said mechanism to prevent firing.

By the provision of a single trigger member according to the presentinvention for operating the sear during firing as well as for settingand looking the firing mechanism, this mechanism is considerablysimplified, which not only facilitates the handling of the firearm, butalso increases safety in operation.

In order that the invention may be clearly understood and readilycarried into effect reference may now be had to the accompanying drawingillustrating one embodiment thereof by way of example, and in which:

Figure 1 is a longitudinal section showing the trigger casing with thefiring mechanism in locked position,

Figure 2 is a similar section showing the mechism in the releasedposition with the trigger depressed,

Figure 3 is an elevation of the trigger as seen in the direction of thearrow 8,

Figure 4 is a fragmentary section on the line IVIV of Fig. 2, as seen ina direction from right to left, with the trigger removed,

Figure 5 shows a detail of the setting means Referring to the drawing, Iindicates the casing of the firing mechanism. The said casing may beprovided with a pistol grip or handles according to how the arm is to beused, but these are not shown. The firing mechanism proper comprises thesear, which co-operates with the locking 5 mechanism, and the memberwhich performs various kinds of movement and operates the sear duringfiring if set in a certain manner. This member forms the trigger properof the mechanism and comprises a rod 5 mounted in bearings 2, 3 formedin the casing I. At one end, the rod 5 is provided with an enlargedcylindrical head 6, which is mounted in a bearing 4 of the casing I. Theenlarged head forms a press button for facilitating the operation of thetrigger. At the other end, the rod 5 is rounded at l, and this roundedend co-operates with the arm 8 of the sear which is rockably mounted ona pin 9. The other arm ID of the sear coacts with a spring I3 whichurges its outer end into the recoil path of the breech mechanism. In theexample shown, this mechanism comprises a breech block carrier l2, witha projection II with which the arm 10 of the sear co-operates. IAccording to the invention, the trigger 5 is provided with means forsetting and locking the mechanism for firing single shots or a series ofshots and for locking the mechanism for preventing firing.

For setting the firing mechanism, there is provided an arrangement :0(Figure 6), which consists of a recess on the periphery of thecylindrical press button 6. The recess is bounded partly by an end face[5 and partly by longitudinal grooves I6, "5, which are formed on theperiphery in the direction of the longitudinal axis of the trigger 5.The width of the longitudinal grooves l6, 16' corresponds to the widthof a projection M. The said projection is provided on the bearing 4 andextends into the bore thereof. The press button is furthermore providedwith a thumb piece I! for facilitating the operation of the trigger 5during the rotary movement thereof. This thumb piece also forms anindicator for indicating the set position'of the trigger 5, thepositions being marked on the outer surface of the casing I by suitableindicia.

Between the bearings 2 and 3, the rod 5 is of rectangular cross sectionand carries a disc 20 having a long boss 23. The disc 20 is providedwith means co-operating with the stationary parts of the firingmechanism and adapted to locate the trigger in set position. This meansmay comprise a knife-edged radial ridge 26 formed on the face of thedisc 20 adjacent the bearing 2 55 (Figure 5). Radial recesses 21 (Figure4) are provided on the adjacent end face of the bearing 2, said recessesbeing spaced through 45 and corresponding in shape to the ridge 28engaging in them in accordance with the setting. Bearing against thedisc 28 is a spring 39 disposed concentrically to the rod 5 and bearingat its other end against a shoulder 28 provided on the rod 5.

The spring 38 firstly loads the disc 2%, so as'to' cause engagement ofthe ridge 2% thereof with the recess 2?, secondly it returns the triggerafter firing into its initial position, wherein the shoulder 28 isapplied to the bearing 3.

In addition to the said positioning means, the disc 20 carries means forco-operating with the sear l0 and forming locking means for the firingmechanism. These means may comprise an arm 2|, which co-operates with aprojection 22 formed on the arm i 9 of the sear.

For firing a shot, the marksman presses withv his finger upon the pressbutton of the trigger 5, the sliding movement being transmitted to thesear 8 which releases the breech block member I 2 and the projection i iwhereof operates the firing pin in known manner.

In the position shown in Figure 1, the firing mechanism is locked, sothat no shot can be fired. In the locked position, the projection I i ofthe bearing 4 is located opposite the end face i 5 (Figures 1 and 6) ofthe press button 6 and prevents sliding longitudinal movement in thedirection of the arrow 8. In this position not only the trigger islocked, which is prevented from sliding longitudinal movement, but alsothe sear, since the arm 2! of the disc 20 is located opposite theprojection 22 and thereby prevents the sear from rocking which mightoccur unintentionally when the gun is shaken. Accidental discharge isthereby prevented. By rotation of the press button 6 With the aid of theoperating thumb piece H to the right or to the left through an angle of45 (Figure 3) the firing mechanism is set for firing. One position maybe for firing single shots and the other for firing a series of shots,it being understood that the firing mechanism is provided with aninterrrupter for firing single shots, which may be of any knownconstruction and is not shown for this reason. During the rotation ofthe press button 6, the rectangular portionZE 'of the rod carries thedisc 28 with it, whereby the ridge 26 is disengaged from the recess 21.During this movement the disc 26 is axially displaced on the trigger rod5 to an amount corresponding to the height of the ridge 26 and therebycompresses the spring 3!). Upon rotation through an angle of 45, theprojection M of the bearing abuts against the side of the slot 56 or it,so that further rotation is prevented and the firing mechanism is setfor firing, since the projection or arm 2! of the disc 29 does notoppose the movement of the sear. When the trigger has been set into thecorresponding position, the ridge 26 engages in another radial recess 21on the bearing 2, since it is pressed by the spring 3t] acting upon thedisc 20, and the mechanism is set for firing. The projection M isopposite the slot IE or if of the press button, so that it does notprevent sliding longitudinal movement of the trigger, which is necessaryfor the operation of the sear 8 during firing. 1

What I claim is: v

1. A firing control mechanism for automatic firearms comprising acasing, a trigger rotatably and slidably mounted in said casing, a scar,a press button on said trigger, a bearing for said press button having aprojection and said press button having recesses cooperating with saidprojection to permit slidable movement of said trigger at onlycertain-predetermined rotary positions thereof and prevent slidablemovement of said :trigger at other rotary positions thereof.

2. A firing control mechanism for automatic firearms comprising acasing, a trigger rotatably and. slidably mounted in said casing, asear, a

'press button on said trigger, a bearing for said press button having aprojection and said press button having recesses cooperating with saidprojection to permit slidable movement of said trig- I ger at onlycertain predetermined rotary positions thereof and the end face of saidpress button being designed to cooperate with said projection to preventslidable movement of said trigger at other rotary positions thereof.

3. A firing control mechanism for automatic firearms comprising acasing, a trigger rotatably and slidably mounted in said casing, a scar,a disc non-rotatably mounted on said trigger, means on said disccooperating with said sear for locking the same and means on said discfor fixing said trigger in certain positions to which it may be rotatedfor controlling the firing.

4. A firing control mechanism for automatic firearms comprising acasing, a trigger rotatably and slidably mounted in said casing, a scar,a disc non-rotatably mounted on said trigger, means on said disccooperating with said sear for locking the same, a bearing for saidtrigger having radial slots therein and a radial ridge on said disccooperating with said slots for fixing the trigger in certainpredetermined positions.

5. A firing control mechanism for automatic firearms comprising acasing, a trigger rotatably and slidably mounted in said casing, a sear,a disc non-rotatably mounted on said trigger, means on said disccooperating with said sear for locking the same, a bearing for saidtrigger having radial slots therein and a radial ridge on said disccooperating with said slots for fixing the trigger in certainpredetermined positions, and a spring urging said ridge into said slots,and returning said trigger to initial position.

6. A firing control mechanism for automatic firearms comprising acasing, a trigger rotatably and slidably mounted in said casing, a scar,a disc non-rotatably mounted on said trigger, means on said disccooperating with said sear for locking the same, a bearing for saidtrigger having radial slots therein and a radial ridge on said disccooperating with said slots for fixing the trigger in certainpredetermined positions and a spring urging said ridge into said slotsand returning said trigger to initial position, and a second bear-- ingfor said trigger limiting the return of said trigger under the influenceof said spring.

7. A firing control mechanism for automatic firearms comprising acasing, a trigger rotatably and slidably mounted in said casing, a sear,said sear being pivotally mounted and having a projection thereon, adisc mounted on said trigger and said disc having a projection adaptedto cooperate with said projection on said sear in order to preventpivotal movement of said sear at a H

